My girlfriend saw me texting my ex-girlfriend asking for reconciliation, and it was the day we just talked. She was very angry. What should I do?

Emotional problems are really annoying. It doesn't matter. You tell him your most sincere words. If you really like her, let him know even without any modification. She will understand your heart. Don't try to make up a story to deceive him. The more she does, the less she believes it. Believe in yourself and be honest with each other. She really likes you, and she will forgive you even if you are wrong.